The research is divided into two areas. The first broadly concerns characterization of the autoantibody response in autoimmune diseases. Specifically the evolution, persistence, and idiotypic relationships of monoclonal autoantibodies of various specificities in serum of individuals with Felty's syndrome and Sjogren's disease are under study. The second area broadly involves elucidating the physical processes and the abnormalities of primary structure which are responsible for the self-association of monoclonal IgG cryoglobulins at reduced temperature. The definition of these properties will lead to an understanding of how these proteins mediate the vascular injury characteristic of the immunocryopathies. The experimental methodology for both projects relies heavily on protein purification and fragmentation, peptide separation and primary amino acid sequence analysis. The physical self-association of the cryoglobulins is studied by circular dichroism, laser-Raman spectroscopy and computer-analyzed analytical ultracentrifugation techniques.